Heat-transfer fluids and use thereof in countercurrent heat exchangers

ABSTRACT

The invention relates to a ternary composition comprising difluoromethane, 1,3,3,3-tetrafluoropropene and a hydrocarbon-derived compound containing at least two fluorine atoms and having a boiling point of between −30 and −20° C., which is selected from 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and 2,3,3,3-tetrafluoropropene. This composition is particularly suitable for use as a heat-transfer fluid in the presence of countercurrent heat exchangers.

FIELD OF THE INVENTION

The present invention relates to heat-transfer fluids suitable for usein countercurrent heat exchangers.

TECHNICAL BACKGROUND

Fluids based on fluorocarbon compounds are widely used invapor-compression heat-transfer systems, in particular air conditioning,heat pump, refrigeration and freezing devices. These devices have incommon the fact that they are based on a thermodynamic cycle comprisingthe vaporization of the fluid at low pressure (in which the fluidabsorbs heat); the compression of the vaporized fluid up to a highpressure; the condensation of the vaporized fluid to liquid at highpressure (in which the fluid releases heat); and the expansion of thefluid in order to complete the cycle.

Vapor compression heat-transfer systems comprise at least two heatexchangers, one in which the fluid vaporizes, and the other in which itcondenses. Heat exchangers may be of cocurrent type or of countercurrenttype.

The choice of a heat-transfer fluid (which may be a pure compound or amixture of compounds) is dictated, on the one hand, by the thermodynamicproperties of the fluid, and on the other hand, by additionalconstraints. Thus, one particularly important criterion is that of theimpact of the fluid considered on the environment. In particular, chlorrated compounds (chlorofluorocarbons and hydrochlorofluorocarbons) havethe disadvantage of damaging the ozone layer. Henceforth, generallynon-chlorinated compounds such as hydrofluorocarbons, fluoroethers andfluoroolefins are therefore preferred to them.

Heat-transfer fluids currently used are HFC-134a, R404a (ternary mixtureof 52% of HFC-143a, 44% of HFC-125 and 4% HFC-134a), R407c (ternarymixture of 52% of HFC-134a, 25% of HFC-125 and 23% of HFC-32) and R410a(binary mixture of 50% of HFC-32 and 50% of HFC-125).

It is, however, necessary to develop other heat-transfer fluids thathave a global warming potential (GWP) lower than that of the fluidsabove, and that have equivalent or improved performance levels.

Document. WO 2007/002625 describes compositions based on fluoro olefins,and in particular on HFO-1234yf or on HFO-1234ze, in various uses, andin particular as heat-transfer fluids. The document does not specify thetype of heat exchanger used.

Document WO 2007/126414 describes generally a large variety offluoroolefin-based compositions and a large variety of uses of thesecompositions. The document does not specify the type of heat exchangerused.

Documents WO 2009/107364, WO 2009/110228 and WO 2009/116282 describerefrigeration apparatuses in which the refrigerants used are mixturesbased on HFO-1234yf and on HFC-32, optionally supplemented or replacedwith other compounds, such as HFC-125. The type of heat exchanger usedis not specified.

Document. US 2009/0158771 describes the use of a ternary mixturecomprising HFC-32, HFC-134a and HFO-1243zf, in a heat transferapplication. The coefficients of performance that are obtained are lowerthan those of the fluid taken as reference, namely HFC-134a. The type ofheat exchanger used is not specified.

Document. WO 2009/150763 describes an air-conditioning apparatus with acountercurrent heat exchanger, in which the heat-transfer fluid is amixture of an HFO-1234 and of HFC-32 or of HFC-41.

Document WO 2010/000993 describes the use of a ternary mixturecomprising HFO-1234yf, HFC-32 and HFC-134a, as a heat-transfer fluid.The document does not specify the type of heat exchanger used.

Document WO 2010/000994 describes the use of a ternary mixturecomprising HFO-1234yf, HFC-32 and HFC-152a, as a heat-transfer fluid.The document does not specify the type of heat exchanger used.

However, there is still a need to develop other heat-transfer fluidsthat have a relatively low. GWP and that have good energy performancelevels, in particular in applications using countercurrent heatexchangers.

SUMMARY OF THE INVENTION

The invention relates firstly to a ternary composition comprisingdifluoromethane, 1,3,3,3-tetrafluoropropene and a hydrocarbon-derivedcompound containing at least two fluorine atoms and having a boilingpoint, of between −30 and −20°, which is selected from1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and2,3,3,3-tetrafluoropropene.

According to one embodiment, the composition comprises difluoromethane,1,1-difluoroethane and 1,3,3,3-tetrafluoro-propene, preferably from 2 to96% of difluoromethane, from 2 to 96% of 1,1-difluoroethane and from 2to 96% of 1,3,3,3-tetrafluoropropene, and particularly preferably:

-   -   from 25 to 50% of difluoromethane, from 2 to 35% of        1,1-difluoroethane and from 15 to 73% of tetrafluoropropene,        ideally from 35 to 50% of di-fluoromethane, from 2 to 10% of        1,1-difluoroethane and from 40 to 63% of        1,3,3,3-tetrafluoropropene; or    -   from 65 to 96% of difluoromethane, from 2 to 20% of        1,1-difluoroethane and from 2 to 25% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        di-fluoromethane, from 2 to 10% of 1,1-difluoroethane and from 5        to 25% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 20% of difluoromethane, from 2 to 85% of        1,1-difluoroethane and from 10 to 96% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        di-fluoromethane, from 2 to 35% of 1,1-difluoroethane and from        50 to 93% of 1,3,3,3-tetrafluoropropene; or    -   from 20 to 50% of difluoromethane, from 2 to 65% of        1,1-difluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        di-fluoromethane, from 2 to 15% of 1,1-difluoroethane and from        35 to 73% of 1,3,3,3-tetrafluoropropene; or    -   from 65 to 93% of difluoromethane, from 2 to 30% of        1,1-difluoroethane and from 5 to of 1,3,3,3-tetrafluoropropene,        ideally from 65 to 93% of di-fluoromethane, from 2 to 10% of        1,1-difluoroethane and from 5 to 33% of        1,3,3,3-tetrafluoropropene.

According to another embodiment, the composition comprisesdifluoromethane, 2,3,3,3-tetrafluoropropene and1,3,3,3-tetrafluoropropene, preferably from 2 to 96% of difluoromethane,from 2 to 96% of 2,3,3,3-tetrafluoropropene and from 2 to 96% of1,3,3,3-tetrafluoropropene, and particularly preferably:

-   -   from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 20 to 60% of        difluoromethane and from 5 to 75% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 5 to 55% of        1,3,3,3-tetrafluoropropene; or    -   from 2 to 50% of 2,3,3,3-tetrafluoropropene, from 50 to 96% of        difluoromethane and from 2 to 40% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 25% of        1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 2 to 20% of        difluoromethane and from 10 to 83% of        1,3,3,3-tetrafluoropropene, ideally from 10 to 75% of        2,3,3,3-tetrafluoropropene, from 5 to 15% of difluoromethane and        from 10 to 75% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 15 to 70% of        difluoromethane and from 5 to 80% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 65% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 10 to 70% of        1,3,3,3-tetrafluoropropene; or    -   from 5 to 45% of 2,3,3,3-tetrafluoropropene, from 50 to 90% of        difluoromethane and from 5 to 45% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 30% of        1,3,3,3-tetrafluoropropene.

According to another embodiment, the composition comprisesdifluoromethane, 1,1,1,2-tetrafluoroethane and1,3,3,3-tetra-fluoropropene, preferably from 2 to 96% ofdifluoromethane, from to 96% of 1,1,1,2-tetrafluoroethane and from 2 to96% of 1,3,3,3-tetrafluoropropene, and particularly preferably:

-   -   from 20 to 60% of difluoromethane, from 2 to 60% of        1,1,1,2-tetrafluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetrafluoroethane and        from 10 to 70% of 1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 30% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 25% of difluoromethane, from 5 to 88% of        1,1,1,2-tetrafluoroethane and from 10 to 93% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetrafluoroethane and        from 25 to 90% of 1,3,3,3-tetra-fluoropropene; or    -   from 15 to 50% of difluoromethane, from 5 to 65% of        1,1,1,2-tetrafluoroethane and from 10 to 80% of        1,3,3,3-tetrafluoropropene, ideally from 15 to 35% of        difluoromethane, from 5 to 55% of 1,1,1,2-tetrafluoroethane and        from 10 to 80% of 1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 25% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene.

According to another embodiment, the composition comprises from 70 to98% of difluoromethane, from 1 to 28% of 2,3,3,3-tetrafluoropropene andfrom 1 to 15% of 1,3,3,3-tetrafluoropropene.

According to one embodiment, the composition comprises from 80 to 98% ofdifluoromethane, from 1 to 18% of 1,1,1,2-tetrafluoroethane and from 1to 12% of 1,3,3,3-tetrafluoropropene.

The invention also relates to the use of the above-mentionedcomposition, as a heat-transfer fluid in a vapor compression circuit.

According to one embodiment, the vapor compression circuit comprises acountercurrent heat exchanger.

The invention also relates to a heat-transfer composition comprising theabovementioned composition as heat-transfer fluid, and one or moreadditives selected from lubricants, stabilizers, surfactants, tracers,fluorescent agents, odorous agents, solubilizing agents and mixturesthereof.

The invention also relates to heat-transfer equipment comprising a vaporcompression circuit containing the above-mentioned composition asheat-transfer fluid or containing the abovementioned heat-transfercomposition.

According to one embodiment, the equipment comprises a countercurrentheat exchanger.

According to one embodiment, the equipment is selected from mobile orstationary equipment for heating via a heat pump, for air conditioning,for refrigeration and for freezing.

The invention also relates to a process for heating or cooling a fluidor a body by means of a vapor compression circuit containing aheat-transfer fluid, said process successively comprising theevaporation of the heat-transfer fluid, the compression of theheat-transfer fluid, the condensation of the heat fluid and theexpansion of the heat-transfer fluid, in which the heat-transfer fluidis the composition according to the invention.

According to one embodiment, the abovementioned process is a process forcooling a fluid or a body, in which the temperature of the fluid or ofthe body cooled is from −40° C. to −10° C., and preferably from −35° C.to −25° C., more particularly preferably from −30° C. to −20° C., and inwhich the heat-transfer fluid comprises:

-   -   from 25 to 50% of difluoromethane, from 2 to 35% of        1,1-difluoroethane and from 15 to 73% of        1,3,3,3-tetrafluoropropene, ideally from 35 to 50% of        difluoromethane, from 2 to 10% of 1,1-difluoroethane and from 40        to 63% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 20 to 60% of        difluoromethane and from 5 to 75% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 5 to 55% of        1,3,3,3-tetrafluoropropene; or    -   from 20 to 60% of difluoromethane, from 2 to 60% of        1,1,1,2-tetrafluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetra-fluoroethane and        from 10 to 70% of 1,3,3,3-tetra-fluoropropene; or    -   from 65 to 96% of difluoromethane, from 2 to 20% of        1,1-difluoroethane and from 2 to 25% of        1,3,3,3-tetrafloropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 10% of 1,1-difluoroethane and from 5        to 25% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 50% of 2,3,3,3-tetrafluoropropene, from 50 to 96% of        difluoromethane and from 2 to 40% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 25% of        1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 30% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene.

According to one embodiment, the abovementioned process is a process forcooling a fluid or a body, in which the temperature of the fluid or ofthe body cooled is from −15° C. to 15° C., and preferably from −10° C.to 10° C., more particularly preferably from −5° C. to 5° C., and inwhich the heat-transfer fluid comprises:

-   -   from 2 to 20% of difluoromethane, from 2 to 85% of        1,1-difluoroethane and from 10 to 96% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 2 to 35% of 1,1-difluoroethane and from 50        to 93% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 2 to 20% of        difluoromethane and from 10 to 83% of        1,3,3,3-tetrafluoropropene, ideally from 10 to 75% of        2,3,3,3-tetrafluoropropene, from 5 to 15% of difluoromethane and        from 10 to 75% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 25% of difluoromethane, from 5 to 88% of        1,1,1,2-tetrafluoroethane and from 10 to 93% of        tetrafluoropropene, ideally from 5 to 15% of difluoromethane,        from 5 to 60% of 1,1,1,2-tetrafluoroethane and from 25 to 90% of        1,3,3,3-tetra-fluoropropene; or    -   from 20 to 50% of difluoromethane, from 2 to 65% of        1,1-difluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        difluoromethane, from 2 to 15% of 1,1-difluoroethane and from 35        to 73% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 15 to 70% of        difluoromethane and from 5 to 80% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 65% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 10 to 70% of        1,3,3,3-tetrafluoropropene; or    -   from 15 to 50% of difluoromethane, from 5 to 65% of        1,1,1,2-tetrafluoroethane and from 10 to 80% of        1,3,3,3-tetrafluoropropene, ideally from 15 to 35% of        difluoromethane, from 5 to 55% of 1,1,1,2-tetrafluoroethane and        from 10 to 80% of 1,3,3,3-tetrafluoropropene; or    -   from 65 to 93% of difluoromethane, from 2 to 30% of        1,1-difluoroethane and from 5 to 33% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 10% of 1,1-difluoroethane and from 5        to 33% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 45% of 2,3,3,3-tetrafluoropropene, from 50 to 90% of        difluoromethane and from 5 to 45% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 30% of        1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 25% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene.

According to one embodiment, the abovementioned process is a process forheating a fluid or a body, in which the temperature of the fluid or ofthe body heated is from 30° C. to 80° C., and preferably from 35° C. to55° C., more particularly preferably from 40° C. to 50° C., in which theheat-transfer fluid comprises:

-   -   from 2 to 20% of difluoromethane, from 2 to 85% of        1,1-difluoroethane and from 10 to 96% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 2 to 35% of 1,1-difluoroethane and from 50        to 93% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 2 to 20% of        difluoromethane and from 10 to 83% of        1,3,3,3-tetrafluoropropene, ideally from 10 to 75% of        2,3,3,3-tetrafluoropropene, from 5 to 15% of difluoromethane and        from 10 to 75% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 25% of difluoromethane, from 5 to 88% of        1,1,1,2-tetrafluoroethane and from 10 to 93% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetrafluoroethane and        from 25 to 90% of 1,3,3,3-tetrafluoropropene; or    -   from 20 to 50% of difluoromethane, from 2 to 65% of        1,1-difluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 23 to 50% of        difluoromethane, from 2 to 15% of 1,1-difluoroethane and from 35        to 73% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 15 to 70% of        difluoromethane and from 5 to 80% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 65% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 10 to 70% of        1,3,3,3-tetrafluoropropene; or    -   from 15 to 50% of difluoromethane, from 5 to 65% of        1,1,1,2-tetrafluoroethane and from 10 to 80% of        1,3,3,3-tetrafluoropropene, ideally from 15 to 35% of        difluoromethane, from 5 to 55% of 1,1,1,2-tetrafluoroethane and        from 10 to 80% of 1,3,3,3-tetra-fluoropropene; or    -   from 65 to 93% of difluoromethane, from 2 to 30% of        1,1-difluoroethane and from 5 to 33% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 10% of 1,1-difluoroethane and from 5        to 33% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 45% of 2,3,3,3-tetrafluoropropene, from 50 to 90% of        difluoromethane and from 5 to 45% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 30% of        1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 25% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene.

The invention also relates to a process for reducing the environmentalimpact of heat-transfer equipment comprising a vapor compression circuitcontaining an initial heat-transfer fluid, said process comprising astep of replacing the initial heat-transfer fluid in the vaporcompression circuit with a final transfer fluid, the final transferfluid having a GWP lower than the initial heat-transfer fluid, in whichthe final heat-transfer fluid is a composition according to theinvention.

According to one embodiment of said process for reducing theenvironmental impact, the initial heat-transfer fluid is a ternarymixture of 52% of 1,1,1-trifluoroethane, 44% of pentafluoroethane and 4%of 1,1,1,2-tetrafluoroethane or a ternary mixture of 52% of1,1,1,2-tetrafluoroethane, 25% of pentafluoroethane and 23% ofdifluoromethane, and in which the final heat-transfer fluid comprises;

-   -   from 25 to 50% of difluoromethane, from 2 to 35% of        1,1-difluoroethane and from 15 to 73% of        1,3,3,3-tetrafluoropropene, ideally from to 50% of        difluorometnane, from 2 to 10% of 1,1-difluoroethane and from 40        to 63% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 20 to 60% of        difluoromethane and from 5 to 75% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 70% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 5 to 55% of        1,3,3,3-tetrafluoropropene; or    -   from 20 to 60% of difluoromethane, from 2 to 60% of        1,1,1,2-tetrafluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetrafluoro-ethane and        from 10 to 70% of 1,3,3,3-tetrafluoropropene; or    -   from 20 to 50% of difluoromethane, from 2 to 65% of        1,1-difluoroethane and from 5 to 78% of        1,3,3,3-tetrafluoropropene, ideally from 25 to 50% of        difluoromethane, from 2 to 15% of 1,1-difluoroethane and from 35        to 73% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 15 to 70% of        difluoromethane and from 5 to 80% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 65% of 2,3,3,3-tetrafluoropropene, from 25 to        50% of difluoromethane and from 10 to 70% of        1,3,3,3-tetrafluoropropene; or    -   from 15 to 50% of difluoromethane, from 5 to 65% of        1,1,1,2-tetrafluoroethane and from 10 to 80% of        1,3,3,3-tetrafluoropropene, ideally from 15 to 35% of        difluoromethane, from 5 to 55% of 1,1,1,2-tetrafluoroethane and        from 10 to 80% of 1,3,3,3-tetrafluoropropene.

According to another embodiment of said process for reducingenvironmental impact, the initial heat-transfer fluid is a binarymixture of 50% of difluoromethane and 50% of pentafluoroethane, and inwhich the final heat-transfer fluid comprises:

-   -   from 65 to 96% of difluoromethane, from 2 to 20% of        1,1-difluoroethane and from 2 to 25% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 10% of 1,1-difluoroethane and from 5        to 25% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 50% of 2,3,3,3-tetrafluoropropene, from 50 to 96% of        difluoromethane and from 2 to 40% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 25% of        1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoropropene and from 5 to 48% of        1,3,3,3-tetrafluoroethane, ideally from 65 to 93% of        difluoromethane, from 2 to 30% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene; or    -   from 65 to 93% of difluoromethane, from 2 to 30% of        1,1-difluoroethane and from 5 to of 1,3,3,3-tetrafluoropropene,        ideally from 65 to 93% of difluoromethane, from 2 to 10% of        1,1′-difluoroethane and from 5 to 33% of        1,3,3,3-tetrafluoropropene; or    -   from 5 to 45% of 2,3,3,3,-tetrafluoropropene, from 50 to 90% of        difluoromethane and from 5 to 45% of 1,3,3,3-tetrafluoropropene,        ideally from 5 to 30% of 2,3,3,3-tetrafluoropropene, from 65 to        90% of difluoromethane and from 5 to 30% of        1,3,3,3-tetrafluoropropene; or    -   from 50 to 93% of difluoromethane, from 2 to 45% of        1,1,1,2-tetrafluoroethane and from 5 to 48% of        1,3,3,3-tetrafluoropropene, ideally from 65 to 93% of        difluoromethane, from 2 to 25% of 1,1,1,2-tetrafluoroethane and        from 5 to 33% of 1,3,3,3-tetrafluoropropene.

According to another embodiment of said process for reducingenvironmental impact, the initial heat-transfer fluid is1,1,1,2-tetrafluoroethane, and in which the final heat-transfer fluidcomprises:

-   -   from 2 to 20% of difluoromethane, from 2 to 85% of        1,1-difluoroethane and from 10 to 96% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 2 to 35% of 1,1-difluoroethane and from 50        to 93% of 1,3,3,3-tetrafluoropropene; or    -   from 5 to 75% of 2,3,3,3-tetrafluoropropene, from 2 to 20% of        difluoromethane and from 10 to 83% of        1,3,3,3-tetrafluoropropene, ideally from 10 to 75% of        2,3,3,3-tetrafluoropropene, from 5 to 15% of difluoromethane and        from 10 to 75% of 1,3,3,3-tetrafluoropropene; or    -   from 2 to 25% of difluoromethane, from 5 to 88% of        1,1,1,2-tetrafluoroethane and from 10 to 93% of        1,3,3,3-tetrafluoropropene, ideally from 5 to 15% of        difluoromethane, from 5 to 60% of 1,1,1,2-tetrafluoroethane and        from 25 to 90% of 1,3,3,3-tetra-fluoropropene.

The present invention makes it possible to overcome the drawbacks of theprior art. It provides more particularly heat-transfer fluids that havea relatively low GWP and that have good energy performance levels, inparticular in applications using countercurrent heat exchangers.

This is accomplished by virtue of ternary mixtures comprising HFO-1234zeand HFC-32, the rest making up the mixtures being selected fromHFO-152a, HFO-1234yf and HFC-134a. These three compounds arehydrocarbon-based molecules which have at least two fluorinesubstituents and a boiling point of between −30° C. and −18° C. HFC-152ahas a boiling point of −24° C., HFO-1234yf has a boiling point of −29°C. and HFC-134a has a boiling point of −26° C.

The ternary mixtures above have the particularity of exhibiting goodenergy performance levels, in particular with countercurrent heatexchangers.

According to some particular embodiments, the invention also has one orpreferably more of the advantageous characteristics listed below.

-   -   The heat-transfer fluids of the invention have a coefficient of        performance which is higher than the reference refrigerants        R404a, R407c, HFC-134a and R410a in applications involving a        countercurrent heat exchanger. In certain cases, the capacity of        the heat-transfer fluids is greater than or equal to that of the        reference refrigerants, in these same applications.        Correspondingly, the invention makes it possible to reduce the        GWP of existing systems comprising one of the above reference        refrigerants, without being detrimental to the performance        levels of these systems, and, on the contrary, while improving        them to a large extent, by replacing the reference refrigerants        with the heat-transfer fluids of the invention.    -   The heat-transfer fluids of the invention have a coefficient of        performance which is higher than that of the        HFO-1243zf/HFC-134a/HFC-32 mixture such as is used in document        US 2009/0158771.    -   The heat-transfer fluids of the invention are less inflammable        and/or more effective than those used in document WO        2009/150763.

according to the invention, the global warming potential (GWP) isdefined relative to carbon dioxide and with respect to a period of 100years, according to the method indicated in “The scientific assessmentof ozone depletion, 2002, a report of the World MeteorologicalAssociation's Global Ozone Research and Monitoring Project”.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention is now described in greater detail and in a non-limitingmanner in the description which follows.

The term “heat-transfer compound”, respectively “heat-transfer fluid”(or refrigerant fluid) is intended to mean a compound, respectively afluid, capable of absorbing heat by evaporating at low temperature andlow pressure and of releasing heat by condensing at high temperature andhigh pressure, in a vapor compression circuit. Generally, aheat-transfer fluid may comprise just one, or two, three or more thanthree heat-transfer compounds.

The term “heat-transfer composition” is intended to mean a compositioncomprising a heat-transfer fluid and, optionally, one or more additiveswhich are not heat-transfer compounds for the envisioned application.

The heat transfer process according to the invention is based on the useof equipment comprising a vapor compression circuit which contains aheat-transfer fluid. The heat-transfer process may be a process forheating or cooling a fluid or body.

The vapor compression circuit containing a heat-transfer fluid comprisesat least one evaporator, a compressor, a condenser and an expansionvalve, and also is for transporting heat-transfer fluid between thesecomponents. The evaporator and the condenser comprise a heat exchangermaking it possible to exchange heat between the heat-transfer fluid andanother fluid or body.

By way of compressor, use may in particular be made of a centrifugalcompressor having one or more stages or a centrifugal mini-compressor.Rotary compressors, reciprocating compressors or screw compressors canalso be used. The compressor may be driven by an electric motor or by agas turbine (for example fed with the exhaust gases of a vehicle, formobile applications), or by gearing.

The equipment may comprise a turbine for generating electricity (Rankinecycle).

The equipment may also optionally comprise at least one coolant circuitused for transmitting heat (with or without a change of state) betweenthe heat-transfer fluid circuit and the fluid or body to be heated orcooled.

The equipment may also optionally comprise two (or more) vaporcompression circuits containing identical or distinct heat-transferfluids. For example, the vapor compression circuits may be coupledtogether.

The vapor compression circuit operates according to a conventional vaporcompression cycle. The cycle comprises the change of state of theheat-transfer fluid from a liquid phase or liquid/vapor two phase state)to a vapor phase at a relatively low pressure, then the compression ofthe fluid in the vapor phase up to a relatively high pressure, thechange of state (condensation) of the heat-transfer fluid from the vaporphase to the liquid phase at a relatively high pressure, and thereduction of the pressure in order to recommence the cycle.

In the case of a cooling process, heat from the fluid or from the bodythat is being cooled (directly or indirectly, via a coolant) is absorbedby the heat-transfer fluid, during the evaporation of the latter, at arelatively low temperature compared with the surroundings. The coolingprocesses include air-conditioning processes (with mobile equipment, forexample in vehicles, or stationary equipment), refrigeration processesand freezing processes or cryogenic processes.

In the case of a heating process, heat is imparted (directly orindirectly, via, a coolant) from the heat-transfer fluid, during thecondensation thereof, to the fluid or the body that is being heated, ata relatively high temperature compared to the surroundings. Theequipment that makes it possible to implement the heat transfer iscalled, in this case, a “heat pump”.

It is possible to use any type of heat exchanger for using theheat-transfer fluids according to the invention, and in particularcocurrent heat exchangers.

However, according to a preferred embodiment, the invention provides forthe cooling and heating processes, and the corresponding equipment, tocomprise a countercurrent heat exchanger, said heat exchanger beingcountercurrent with respect either to the condenser or to theevaporator. Indeed, the heat-transfer fluids according to the inventionare particularly effective with countercurrent heat exchangers.Preferably, both the evaporator and the condenser comprise acountercurrent heat exchanger.

According to the invention, the term “countercurrent heat exchanger” isintended to mean a heat exchanger in which the heat is exchanged betweena first fluid and a second fluid, the first fluid at the inlet of theexchanger exchanging heat with the second fluid at the outlet of theexchanger, and the first fluid at the outlet of the exchanger exchangingheat with the second fluid at the inlet of the exchanger.

For example, the countercurrent heat exchangers include devices in whichthe flow of the first fluid and the flow of the second fluid are inopposite directions or virtually opposite directions. Exchangers whichoperate in cross-current mode with countercurrent tendency are alsoincluded among the countercurrent heat exchangers within the meaning ofthe present application.

The meaning of the various abbreviations used to denote the variouschemical compounds mentioned in the application is the following:

-   -   HFC-134a: 1,1,1,2-tetrafluoroethane;    -   HFC-143a: 1,1,1-trifluoroethane;    -   HFC-125: pentafluoroethane;    -   HFC-32: difluoromethane;    -   HFC-152a: 1,1-difluoroethane;    -   HFC-41: fluoromethane;    -   HFO-1234ze: 1,3,3,3-tetrafluoropropene;    -   HFO-1234yf: 2,3,3,3-tetrafluoropropene;    -   HFO-1243zf: 3,3,3-trifluoropropene.

The heat-transfer fluids used in the invention are the following ternarymixtures:

-   -   1) HFC-32, HFC-152a and HFO-1234ze;    -   2) HFO-1234yf, HFC-32 and HFO-1234ze; and    -   3) HFC-32, HFC-134a and HFO-1234ze.

Compositions 2) and 3) have the advantage of being less inflammable thanthose described in document WO 2009/150763.

The term “ternary mixture” is intended to mean a composition consistingessentially of the three compounds mentioned, i.e. in which the threecompounds mentioned represent at least 99% (preferably at least 99.5% oreven at least 99.9%) of the composition.

Unless otherwise mentioned, throughout the application, the proportionsof compounds indicated are given as percentages by weight.

The HFO-1234ze may be in cis or trans form or be a mixture of these twoforms.

In each of the three compositions above, each compound can be presentpreferably in an amount of from 1 to 99%, and in particular from 1 to96%.

For use in low-temperature refrigeration processes, i.e. those in whichthe temperature of the fluid or of the body cooled is from −40° C. to−10° C., and preferably from −35° C. to −25° C., more particularlypreferably from −30° C. to −20° C. (ideally approximately 25° C.) it hasbeen found that the compounds which are most effective as a replacementfor R404a or R407c are the following:

-   -   for composition 1) from 25 to 50% of HFC-32, from 2 to 35% of        HFC-152a and from 15 to 73% of HFO-1234ze, and preferably from        35 to 50% of HFC-32, from 2 to 10% of HFC-152a and from 40 to        63% of HFO-1234ze;    -   for composition 2): from 5 to 70% of HFO-1234yf, from 20 to 60%        of HFC-32 and from 5 to 75% of HFO-1234ze, and preferably from 5        to 70% of HFO-1234yf, from 25 to 50% of HFC-32 and from 5 to 55%        of HFO-1234ze; and    -   for composition 3): from 20 to 60% of HFC-32, from 2 to 60% of        HFC-134a and from 5 to 78% of HFO-1234ze, and preferably from 25        to 50% of HFC-32, from 5 to 60% of HFC-134a and from 10 to 70%        of HFO-1234ze.

For use in low-temperature refrigeration processes, i.e. those in whichthe temperature of the fluid or of the body cooled is from −40° C. to−10° C., and, preferably from −35° C. to −25° C., more particularlypreferably from −30° C. to 20° C. (ideally approximately −25° it hasbeen found that the compositions which are most effective as areplacement for R410a are the following:

-   -   for composition 1): from 65 to 96% of HFC-32, from 2 to 20% of        HFC-152a and from 2 to 25% of HFO-1234ze, and preferably from 65        to 93% of HFC-32, from 2 to 10% of HFC-152a and from 5 to 25% of        HFO-1234ze;    -   for composition 2): from 2 to 50% of HFO-1234yf, from 50 to 96%        of HFC-32 and from 2 to 40% of HFO-1234ze, and preferably from 5        to 30% of HFO-1234yf, from 65 to 90% of HFC-32 and from 5 to 25%        of HFO-1234ze; and    -   for composition 3): from 50 to 93% of HFC-32, from 2 to 45% of        HFC-134a and from 5 to 48% of HFO-1234ze, and preferably from 65        to 93% of HFC-32, from 2 to 30% of HFC-134a and from 5 to 33% of        HFO-1234ze.

For use in

-   -   moderate-temperature cooling processes, i.e. those in which the        temperature of the fluid or the body cooled is from −15° C. to        15° C., preferably from −10° C. to 10° C., more particularly        preferably from 5° C. to 0.5° C. (ideally approximately 0° C.),        and also    -   moderate-temperature heating processes, i.e. those in which the        temperature of the fluid or of the body heated is from 30° C. to        80° C., and preferably from 35° C. to 55° C., more particularly        preferably from 40° C. to 50° C. (ideally approximately 45° C.),        it has been found that the compositions which are most effective        as a replacement for HFC-134a are the following:    -   for composition 1): from 2 to 20% of HFC-32, from 2 to 85% of        HFC-152a and from 10 to 96% of HFO-1234ze, and preferably from 5        to 15% of HFC-32, from 2 to 35% of HFC-152a and from 50 to 93%        of HFO-1234ze;    -   for composition 2): from 5 to 75% of HFO-1234yf, from 2 to 20%        of HFC-32 and from 10 to 83% of HFO-1234ze, and preferably from        10 to 75% of HFO-1234yf, from 5 to 15% of HFC-32 and from 10 to        75% of HFO-1234ze; and    -   for composition 3): from 2 to 25% of HFC-32, from 5 to 88% of        HFC-134a and from 10 to 93% of HFO-1234ze, and preferably from 5        to 15% of HFC-32, from 5 to 60% of HFC-134a and from 25 to 90%        of HFO-1234ze.

For use in

-   -   moderate-temperature cooling processes, i.e. those in which the        temperature of the fluid or of the body cooled is from 15° C. to        15° C., preferably from −10° C. to 10° C., more particularly        preferably from 5° C. to 5° C. (ideally approximately 0° C.),        and also    -   moderate-temperature heating processes, i.e. those in which the        temperature of the fluid or of the body heated is from 30° C. to        80° C., and preferably from 35° C. to 55° C., more particularly        preferably from 40° C. to 50° C. (ideally approximately 45° C.),        it has been found that the compositions which are most effective        as a replacement for R404a or for R407c are the following:    -   for composition 1): from 20 to 50% of HFC-32, from 2 to 65% of        HFC-152a and from 5 to 78% of HFO-1234ze, and ideally from 25 to        50% of HFC-32, from 2 to 15% of HFC 152a and from 35 to 73% of        HFC-1234ze;    -   for composition 2) from 5 to 75% of HFO-1234yf, from 15 to 70%        of HFC-32 and from 5 to 80% of HFO-1234ze, and ideally from 5 to        65% of HFO-1234yf, from 25 to 50% of HFC-32 and from 1.0 to 70%        of HFO-1234ze; and    -   for composition 3) from 15 to 50% of HFC-32, from 5 to 65% of        HFC-134a and from 10 to 80% of HFO-1234ze, and ideally from 15        to 35% of HFC-32, from 5 to 55% of HFC-134a and from 10 to 80%        of HFO-1234ze.

For use in:

-   -   moderate-temperature cooling processes, i.e. those in which the        temperature of the fluid or of the body cooled is from −15° C.        to 15° C., preferably from 10° C. to 10° C., more particularly        preferably from −5° C. to 5° C. (ideally about 0° C.), and also    -   moderate-temperature heating processes, i.e. those in which the        temperature of the fluid or of the body heated is from 30° C. to        80° C., and preferably from 35° C. to 55° C., more particularly        preferably from 40° C. to 50° C. (ideally approximately 45° C.),        it has been found that the compositions which are most effective        as a replacement for R410a are the following:    -   for composition 1): from 65 to 93% of HFC-32, from 2 to 30% of        HFC-152a and from 5 to 33% of HFO-1234ze, and ideally from 65 to        93% of HFC-32, from 2 to 10% of HFC-152a and from 5 to 33% of        HFO-1234ze;    -   for composition 2): from 5 to 45% of HFO-1234yf, from 50 to 90%        of HFC-32 and from 5 to 45% of HFO-1234ze, and ideally from 5 to        30% of HFO-1234yf, from 65 to 90% of HFC-32 and from 5 to 30% of        HFO-1234ze; and    -   for composition 3) from 50 to 93% of HFC-32, from 2 to 45% of        HFC-134a and from 5 to 48% of HFO-1234ze, and ideally from 65 to        93% of HFC-32, from 2 to 25% of HFC-134a and from 5 to 33% of        HFO-'1234ze.

In the “low-temperature refrigeration” processes mentioned above, theinlet temperature of the heat-transfer fluid at the evaporator ispreferably from −45° C. to −15° C., in particular from −40° C. to −20°C., more particularly preferably from −35° C. to −25° C. and, forexample, approximately −30° C.; and the temperature at the beginning ofthe condensation of the heat-transfer fluid at the condenser ispreferably from 25° C. to 80° C., in particular from 30° C. to 60° C.,more particularly preferably from 35° C. to 55° C. and, for example,approximately 40° C.

In the “moderate-temperature refrigeration” processes mentioned above,the inlet temperature of the heat-transfer fluid at the evaporator ispreferably from −20° C. to 10° C., in particular from −15° C. to 5° C.,more particularly preferably from 10° C. to 0° C. and, for example,approximately −5° C.; and the temperature at the beginning of thecondensation of the heat-transfer fluid at the condenser is preferablyfrom 25° C. to 80° C., in particular from 30° C. to 60° C., moreparticularly preferably from 35° C. to 55° C. and, for example,approximately 50° C. These processes may be refrigeration orair-conditioning processes.

In the “moderate-temperature heating” processes mentioned above, theinlet temperature of the heat-transfer fluid at the evaporator ispreferably from 20° C. to 10° C., in particular from −15° C. to 5° C.,more particularly preferably from −10° C. to 0° C. and, for example,approximately −5° C.; and the temperature at the beginning of thecondensation of the heat-transfer fluid at the condenser is preferablyfrom 25° C. to 80° C., in particular from 30° C. to 60° C., moreparticularly preferably from 35° C. to 55° C. and, for example,approximately 50° C.

In addition, the mixtures having the following formulations arequasi-azeotropic mixtures:

-   -   from 1 to 28% of HFO-1234yf, from 70 to 98% HFC-32 and from 1 to        15% of HFO-1234ze;    -   from 80 to 98% of HFC-32, from 1 to 18% of HFC-134a and from 1        to 12% of HFO-1234ze.

For these heat-transfer fluids, at constant temperature, the liquidsaturation pressure and the vapor saturation pressure are virtuallyidentical (the maximum pressure difference being 10%). Theseheat-transfer fluids have an advantage in terms of ease of use, in theabsence of significant temperature glide, there is no significant changein the composition circulating, and no significant change either in thecomposition in the event of a leak. These heat-transfer fluids areparticularly suitable for replacing R410a, for example.

The heat-transfer fluids which are not quasi-azeotropic, for their part,are however very effective when they are correctly coupled with acountercurrent heat exchanger (with a temperature difference with thesecond fluid which is approximately constant in the exchanger).

Each heat-transfer fluid above can be mixed with one or more additivesso as to provide the heat transfer composition actually circulating inthe vapor compression circuit. The additives can in particular beselected from lubricants, stabilizers, surfactants, tracers, fluorescentagents, odorous agents, solubilizing agents and mixtures thereof.

When it (they) is (are) present, the stabilizer(s) preferablyrepresent(s) at most 5% by weight in the heat-transfer composition.Among the stabilizers, mention may in particular be made ofnitromethane, ascorbic acid, terephthalic acid, azoles such astolutriazole or benzotriazole, phenolic compounds such as tocopherol,hydroquinone, t-butyl hydroquinone, 2,6-di-tert-butyl-4-methylphenol,epoxides (alkyl, optionally fluorinated or perfluorinated, or alkenyl oraromatic) such as n-butyl glycidyl ether, hexanediol diglycidyi ether,allyl diglycidyi ether, butylphenyl glycidyl ether, phosphites,phosphonates, thiols and lactones.

By way of lubricants, use may in particular be made of oils of mineralorigin, silicone oils, paraffins, naphthenes, synthetic paraffins,alkylbenzenes, poly-α-olefins, polyalkene glycols, polyol esters and/orpolyvinyl ethers.

By way of tracers (capable of being detected), mention may be made ofhydrofluorocarbons, deuterated hydrofluorocarbons, deuteratedhydrocarbons, perfluorocarbons, fluoroethers, brominated compounds,iodinated compounds, alcohols, aldehydes, ketones, nitrous oxide andcombinations thereof. The tracer is different than the heat-transfercompound (s) making up the heat-transfer fluid.

By way of solubilizing agents, mention may be made of hydrocarbons,dimethyl ether, polyoxyalkylene ethers, amides, ketones, nitriles,chlorocarbons, esters, lactones, aryl ethers, fluoroethers and1,1,1-trifluoroalkanes. The solubilizing agent is different than theheat-transfer compound(s) making up the heat-transfer fluid.

By way of fluorescent agents, mention may be made of naphthalimides,perylenes, coumarins, anthracenes, phenanthracenes, xanthenes,thioxanthenes, naphthoxanthenes, fluoresceins and derivatives andcombinations thereof.

By way of odorous agents, mention may be made of alkyl acrylates, allylacrylates, acrylic acids, acryl esters, alkyl ethers, alkyl esters,alkynes, aldehydes, thiols, thioethers, disulfides, allylisothiocyanates, alkanoic acids, amines, norbornenes, norbornenederivatives, cyclohexene, aromatic heterocyclic compounds, ascaridole,o-methoxy(methyl)phenol and combinations thereof.

The compositions according to the invention can also be used as anexpansion agent, an aerosol or a solvent.

EXAMPLES

The following examples illustrate the invention without limiting it.

Example 1 Method for Calculating the Properties of the Heat-TransferFluids in the Various Configurations Envisioned

The RK-Soave equation is used for the calculation of the densities,enthalpies, entropies and liquid/vapor equilibrium data of the mixtures.The use of this equation requires knowledge of the properties of thepure substances used in the mixtures in question and also theinteraction coefficients for each binary mixture.

The data necessary for each pure substance are the boiling point, thecritical temperature and the critical pressure, the pressure curve as afunction of the temperature from the boiling point up to the criticalpoint, and the saturated liquid and saturated vapor densities as afunction of the temperature.

The data with regard to HFCs are published in the ASHRAE Handbook 2005,chapter 20, and are also available under Refprop (software developed byNIST for the calculation of the properties of refrigerant fluid).

The HFO temperature-pressure curve data are measured by the staticmethod. The critical temperature and the critical pressure are measuredusing a C80 calorimeter sold by Setaram. The densities, at saturation asa function of the temperature, are measured by means of thevibrating-tube densimeter technology developed by the laboratories ofthe école de Mines de Paris [French Engineering School].

The RH-Soave equation uses coefficients of binary interaction torepresent the behavior of products in mixtures. The coefficients arecalculated according to the experimental liquid/vapor equilibrium data.

The technique used for the liquid/vapor equilibrium measurements is thestatic analytical cell method. The equilibrium cell comprises a sapphiretube and is equipped with two Rolsitm electromagnetic samplers. It isimmersed in a cryothermostat bath (Huber HS40). Magnetic stirring drivenby a magnetic field rotating at a variable speed is used to acceleratethe reaching of the equilibria. The sample analysis is carried out bygas chromatography (HP5890 series II) using a katharometer (TCD).

The liquid/vapor equilibrium measurements on the binary mixtureHFC-32/HFO-1234ze are carried out for the following isotherm: 15° C.

The liquid/vapor equilibrium measurements on the binary mixtureHFC-134a/HFO-1234ze are carried out for the following isotherm: 20° C.

The liquid/vapor equilibrium measurements on the binary mixtureHFC-134a/HFO-1234ze are carried out for the following isotherm: 15° C.

The liquid/vapor equilibrium measurements on the binary mixtureHFC-32/HFO-1234yf are carried out for the following isotherms: 70° C.,30° C., −10° C.

The liquid/vapor equilibrium measurements on the binary mixtureHFC-1234ze/HFO-1234yf are carried out for the following isotherm: 18° C.

The liquid/vapor equilibrium data for the binary mixture HFC-152a/HFC-32are available under Refprop. Two isotherms (−20° C. and 20° C.) and twoisobars (1 bar and 25 bar) are used for the calculation of theinteraction coefficients for this binary mixture.

The liquid/vapor equilibrium data for the binary mixture HFC-134a/HFC-32are available under Refprop. Two isotherms (−20° C. and 20° C.) and twoisobars (1 bar and 30 bar) are used for the calculation of theinteraction coefficients for this binary mixture.

A compression system equipped with a countercurrent evaporator andcondenser, with a screw compressor and with an expansion valve isconsidered.

The system operates with 15° C. of overheat, and 5° C. of undercooling.The minimum temperature difference between the secondary fluid and therefrigerant fluid is considered to be about 5° C.

The isentropic efficiency of the compressors depends on the compressionratio. This efficiency is calculated according to the followingequation:

$\begin{matrix}{\eta_{isen} = {a - {{b\left( {\tau - c} \right)}^{2}\frac{d}{\tau - e}}}} & (1)\end{matrix}$

For a screw compressor, the constants a, b, c, d and e of the isentropicefficiency equation (1) are calculated according to the standard datapublished in the “Handbook of air conditioning and refrigeration”, page11.52.

The coefficient of performance (COP) is defined as being the usefulpower supplied by the system over the power provided or consumed by thesystem.

The Lorenz coefficient of performance (COPLorenz) is a referencecoefficient of performance. It depends on temperatures and is used tocompare the COPs of the various fluids.

The Lorenz coefficient of performance is defined as follows (thetemperatures T are in K):

$\begin{matrix}{T_{average}^{condenser} = {T_{inlet}^{condenser} - T_{outlet}^{condenser}}} & (2) \\{T_{average}^{evaporator} = {T_{outlet}^{evaporator} - T_{inlet}^{evaporator}}} & (3)\end{matrix}$

The Lorenz COP in the case of conditioned air and of refrigeration is:

$\begin{matrix}{{COPlorenz} = \frac{T_{average}^{evaporator}}{T_{average}^{condenser} - T_{average}^{evaporator}}} & (4)\end{matrix}$

The Lorenz COP in the case of heating is:

$\begin{matrix}{{COPlorenz} = \frac{T_{average}^{condenser}}{T_{average}^{condenser} - T_{average}^{evaporator}}} & (5)\end{matrix}$

For each composition, the coefficient of performance of the Lorenz cycleis calculated as a function of the corresponding temperatures.

in low-temperature refrigeration mode, the compression system operatesbetween an inlet temperature of the refrigerant fluid at the evaporatorof −30° C. and an inlet temperature of the refrigerant fluid at thecondenser of 40° C. The system provides refrigeration at −25° C.

In moderate-temperature heating mode, the compression system operatesbetween an inlet temperature of the refrigerant fluid at the evaporatorof −5° C. and a temperature at the beginning of the condensation of therefrigerant fluid at the condenser of 50° C. The system supplies heat at45° C.

In moderate-temperature cooling mode, the compression system operatesbetween an inlet temperature of the refrigerant fluid at the evaporatorof −5° C. and a temperature at the beginning of the condensation of therefrigerant fluid at the condenser of 50° C. The system providesrefrigeration at 0° C.

In the tables that follow, “Temp. evap cutlet” denotes the temperatureof the fluid at the outlet of the evaporator, “Temp. comp outlet”denotes the temperature of the fluid at the outlet of the compressor, “Tcond outlet” denotes the temperature of the fluid at the outlet of thecondenser, “evap P” denotes the pressure of the fluid in the evaporator,“cond P” denotes the pressure of the fluid in the condenser, “Ratio(w/w)” denotes the compression ratio, “Glide” denotes the temperatureglide, “comp efficiency” denotes the efficiency of the compressor, “%CAP” denotes the volumetric capacity of the fluid relative to thereference fluid indicated on the first line, “% COP/COPLorenz” denotesthe ratio of the COP of the system relative to the COP of thecorresponding Lorenz cycle, “Psat liquid” denotes the liquid saturationpressure, “Psat vapor” denotes the vapor saturation pressure, and “%diff in pressure” denotes the difference between these two pressures,expressed as a percentage.

Example 2 Results for a Low-Temperature Refrigeration, Comparison withR404a and R407c

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R404A −30 101 40 2.1 18.1 8.8 0.46 53.8 100 32R407C −26 131 35 1.7 15.3 9.0 4.48 51.9 108 35 HFC- HFC- HFO- 32 134a1234ze 25 40 35 −24 133 33 1.4 12.8 9.1 5.64 51.1 94 36 35 60 5 −25 14434 1.7 14.9 8.9 4.97 52.6 111 37 35 50 15 −25 140 34 1.7 14.7 8.8 5.3853.6 111 37 35 40 25 −24 136 33 1.7 14.4 8.7 5.90 54.5 110 38 35 30 35−24 132 33 1.6 14.2 8.6 6.44 55.5 110 39 35 20 45 −23 128 32 1.6 13.98.5 6.99 56.3 110 40 35 10 55 −22 126 32 1.6 13.6 8.4 7.53 57.0 109 4050 45 5 −25 153 35 2.0 17.1 8.6 4.83 55.0 130 38 50 35 15 −25 148 34 2.016.9 8.5 5.30 56.0 130 39 50 25 25 −24 143 34 2.0 16.6 8.4 5.89 57.1 13040 50 15 35 −23 139 33 2.0 16.3 8.2 6.52 58.1 131 41 50 5 45 −23 136 322.0 16.0 8.1 7.14 59.1 131 41HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R404A −30 101 40 2.1 18.1 8.8 0.46 53.8 100 32R407C −26 131 35 1.7 15.3 9.0 4.48 51.9 108 35 HFO- HFC- HFO- 1234yf 321234ze 70 25 5 −25 103 32 1.8 14.7 8.1 5.27 58.9 107 40 60 25 15 −24 10532 1.7 14.3 8.2 5.65 58.5 105 39 50 25 25 −24 106 32 1.7 13.8 8.2 6.1458.4 103 40 40 25 35 −23 107 31 1.6 13.3 8.2 6.62 58.3 102 40 30 25 45−23 108 31 1.6 12.8 8.3 7.04 58.0 99 40 60 35 5 −25 113 34 2.1 16.6 8.15.06 59.5 122 40 50 35 15 −24 114 33 2.0 16.1 8.1 5.63 59.4 120 40 40 3525 −24 114 32 1.9 15.4 8.0 6.29 59.8 119 41 30 35 35 −23 114 31 1.8 14.88.0 6.93 60.0 117 41 20 35 45 −23 116 31 1.8 14.2 8.0 7.46 59.8 115 4210 35 55 −22 118 31 1.7 13.7 8.1 7.85 59.1 112 42 45 50 5 −26 132 36 2.319.3 8.3 3.72 57.9 138 38 35 50 15 −25 132 35 2.3 18.5 8.2 4.66 58.5 13739 25 50 25 −24 131 34 2.2 17.6 8.1 5.63 59.3 136 40 15 50 35 −24 131 332.1 16.8 8.0 6.49 59.8 135 41 5 50 45 −23 133 32 2.0 16.2 8.0 7.17 59.8132 42HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R404A −30 101 40 2.1 18.1 8.8 0.46 53.8 100 32R407C −26 131 35 1.7 15.3 9.0 4.48 51.9 108 35 HFC- HFC- HFO- 32 152a1234ze 35 30 35 −24 152 31 1.5 13.2 9.1 6.21 51.3 105 37 35 20 45 −23140 31 1.5 13.1 8.8 6.96 54.0 106 39 35 10 55 −22 130 31 1.5 13.1 8.57.65 56.3 108 40 50 35 15 −24 176 33 1.7 15.7 9.2 5.96 50.4 122 36 50 2525 −24 162 33 1.8 15.7 8.8 6.39 53.4 125 38 50 15 35 −23 148 32 1.8 15.68.4 7.14 56.6 128 40 50 5 45 −22 137 32 1.9 15.7 8.1 7.64 59.0 130 42

Example 3 Results for Low-Temperature Refrigeration, Comparison withR410a

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R410A −30 153 40 2.7 24.2 8.9 0.06 52.5 100 33 HFC-HFC- HFO- 32 134a 1234ze 65 30 5 −26 167 36 2.2 19.4 8.6 3.91 55.2 96 3865 20 15 −26 162 36 2.3 19.1 8.5 4.40 56.1 96 39 65 10 25 −25 157 35 2.318.9 8.4 5.07 57.3 97 39 80 15 5 −28 185 38 2.5 21.7 8.7 2.49 54.1 10537 80 5 15 −27 180 37 2.5 21.5 8.6 3.01 54.9 105 37 90 5 5 −29 199 392.6 23.3 8.9 1.34 53.0 110 35HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R410A −30 153 40 2.7 24.2 8.9 0.06 52.5 100 33 HFO-HFC- HFO- 1234yf 32 1234ze 30 65 5 −28 155 38 2.5 21.4 8.5 2.22 55.8 9937 20 65 15 −26 154 37 2.4 20.5 8.4 3.55 56.7 99 38 10 65 25 −25 153 352.3 19.4 8.3 4.76 57.8 98 39 15 80 5 −29 180 39 2.6 23.0 8.8 1.19 53.9106 36 5 80 15 −27 179 38 2.5 21.9 8.7 2.69 54.9 106 37 5 90 5 −29 19839 2.7 23.8 8.9 0.82 52.8 110 35HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R410A −30 153 40 2.7 24.2 8.9 0.06 52.5 100 33 HFC-HFC- HFO- 32 152a 1234ze 65 20 15 −24 180 35 2.1 18.4 8.9 5.51 52.6 9336 65 10 25 −24 164 34 2.2 18.4 8.5 5.92 56.0 95 39 80 15 5 −26 201 372.3 21.2 9.1 4.14 51.2 102 34 80 5 15 −26 185 37 2.4 21.3 8.8 3.70 54.1104 36 90 5 5 −28 208 39 2.6 23.1 9.0 2.20 52.0 109 35

Example 4 Results for Moderate-Temperature Cooling, Comparison withHFC-134a

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R134a −5 81 50 2.4 13.2 5.4 0.00 75.9 100 54 HFC-HFC- HFO- 32 134a 1234ze 5 25 70 −3 77 46 2.3 12.0 5.1 2.38 77.3 99 55 535 60 −3 78 47 2.4 12.3 5.1 2.22 77.2 101 55 5 45 50 −3 79 47 2.5 12.75.1 2.05 77.2 103 55 5 55 40 −3 80 47 2.5 13.0 5.1 1.88 77.2 105 55 5 6530 −3 80 48 2.6 13.3 5.1 1.70 77.2 107 55 5 75 20 −3 81 48 2.6 13.6 5.11.53 77.2 109 55 5 85 10 −4 82 48 2.7 13.8 5.1 1.37 77.2 112 55 15 5 801 79 42 3.0 13.3 4.5 6.02 79.6 128 58 15 15 70 1 80 43 3.0 13.7 4.5 5.5279.5 129 58 15 25 60 0 81 44 3.1 14.0 4.5 5.10 79.4 130 58 15 35 50 0 8244 3.1 14.3 4.6 4.72 79.3 132 57 15 45 40 −1 83 44 3.2 14.6 4.6 4.3679.2 133 57 15 55 30 −1 84 45 3.2 15.0 4.6 4.03 79.1 135 57 15 65 20 −185 45 3.3 15.2 4.7 3.71 79.0 136 57 15 75 10 −2 86 46 3.3 15.5 4.7 3.4478.9 138 57HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R134a −5 81 50 2.4 13.2 5.4 0.00 75.9 100 54 HFO-HFC- HFO- 1234yf 32 1234ze 25 5 70 −2 73 46 2.4 11.9 4.9 2.89 78.1 98 5535 5 60 −2 72 46 2.5 12.3 4.8 2.85 78.3 101 55 45 5 50 −2 72 46 2.6 12.74.8 2.75 78.5 103 55 55 5 40 −2 71 46 2.7 13.0 4.7 2.60 78.7 106 55 5 1580 1.2 78 42 3.0 13.3 4.4 6.23 79.8 129 58 15 15 70 1.1 78 42 3.2 13.64.3 6.13 80.1 131 58 25 15 60 1.0 77 42 3.3 14.0 4.3 6.03 80.2 131 58 3515 50 0.9 76 42 3.4 14.5 4.2 5.90 80.3 138 58 45 15 40 0.7 76 43 3.614.9 4.2 5.71 80.4 142 58 55 15 30 0.5 76 43 3.7 15.4 4.2 5.47 80.4 14558 65 15 20 0.2 75 43 3.8 15.9 4.2 5.19 80.5 148 57 75 15 10 −0.1 75 433.9 16.2 4.2 4.93 80.5 149 57HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz HFC-134a −5 81 50 2.4 13.2 5.4 0.00 75.9 100 54HFC- HFC- HFO- 32 152a 1234ze 5 5 90 −3 76 45 2.2 11.2 5.1 2.32 77.1 9356 5 15 80 −3 79 46 2.2 11.4 5.2 1.92 76.9 95 56 5 25 70 −3 81 47 2.311.7 5.2 1.75 76.9 98 56 5 35 60 −3 84 47 2.3 11.9 5.2 1.65 76.9 100 575 45 50 −3 86 47 2.3 12.0 5.2 1.55 77.0 103 57 5 55 40 −4 89 47 2.4 12.25.2 1.43 77.0 105 57 5 65 30 −4 91 47 2.4 12.3 5.2 1.29 77.0 106 58 5 7520 −4 93 47 2.4 12.3 5.2 1.14 76.9 108 58 5 85 10 −4 95 47 2.4 12.3 5.20.97 76.8 108 58 15 5 80 1 80 42 2.9 13.1 4.5 5.61 79.4 126 59 15 15 700 83 43 2.9 13.2 4.6 4.89 79.1 126 59 15 25 60 0 85 43 2.9 13.3 4.7 4.5479.0 128 59 15 35 50 −1 88 43 2.9 13.5 4.7 4.28 78.9 130 59 15 45 40 −190 43 2.9 13.7 4.7 4.00 78.7 131 59 15 55 30 −1 93 43 2.9 13.7 4.8 3.7078.6 132 59 15 65 20 −2 95 44 2.9 13.8 4.8 3.37 78.4 132 59 15 75 10 −298 44 2.8 13.7 4.9 3.04 78.1 132 59

Example 5 Results for moderate-temperature heating, Comparison withHFC-134a

HFC-37/HFC-134a/HFO-1234 ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement%COPc/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R134a −5 81 50 2.4 13.2 5.4 0.00 75.9 100 63HFC- HFC- HFO- 32 134a 1234ze 5 35 60 −3 78 47 2.4 12.3 5.1 2.22 77.2 9964 5 45 50 −3 79 47 2.5 12.7 5.1 2.05 77.2 102 64 5 55 40 −3 80 47 2.513.0 5.1 1.88 77.2 104 64 5 65 30 −3 80 48 2.6 13.3 5.1 1.70 77.2 106 645 75 20 −3 81 48 2.6 13.6 5.1 1.53 77.2 108 64 5 85 10 −3 82 48 2.7 13.85.1 1.37 77.2 110 64 15 5 80 1 79 42 3.0 13.3 4.5 6.02 79.6 121 66 15 1570 1 80 43 3.0 13.7 4.5 5.52 79.5 123 66 15 25 60 0 81 44 3.1 14.0 4.55.10 79.4 124 65 15 35 50 0 82 44 3.1 14.3 4.6 4.72 79.3 125 65 15 45 40−1 83 44 3.2 14.6 4.6 4.36 79.2 127 65 15 55 30 −1 84 45 3.2 15.0 4.64.03 79.1 128 65 15 65 20 −1 85 45 3.3 15.2 4.7 3.71 79.0 130 65 15 7510 −2 86 46 3.3 15.5 4.7 3.44 78.9 132 65HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp T sortie sortie sortie cond evap P cond P Taux rendement %COP/Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p) Glidecomp % CAP COPLorenz R134a −5 81 50 2.4 13.2 5.4 0.00 75.9 100 63 HFO-HFC- HFO- 1234yf 32 1234ze 35 5 60 −2 72 46 2.5 12.3 4.8 2.85 78.3 10064 45 5 50 −2 72 46 2.6 12.7 4.8 2.75 78.5 102 64 55 5 40 −2 71 46 2.713.0 4.7 2.60 78.7 105 64 65 5 30 −3 71 46 2.8 13.4 4.7 2.41 78.8 107 645 15 80 1.2 78 42 3.0 13.3 4.4 6.23 79.8 122 66 15 15 70 1.1 78 42 3.213.6 4.3 6.13 80.1 125 66 25 15 60 1.0 77 42 3.3 14.0 4.3 6.03 80.2 12966 35 15 50 0.9 76 42 3.4 14.5 4.2 5.90 80.3 132 66 45 15 40 0.7 76 433.6 14.9 4.2 5.71 80.4 136 66 55 15 30 0.5 76 43 3.7 15.4 4.2 5.47 80.4139 66 65 15 20 0.2 75 43 3.8 15.9 4.2 5.19 80.5 142 66 75 15 10 −0.1 7543 3.9 16.2 4.2 4.93 80.5 143 65HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COPc/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz HFC-134a −5 81 50 2.4 13.2 5.4 0.00 75.9 10063 HFC-32 HFC-152a HFO-1234ze 5 5 90 −3 76 45 2.2 11.2 5.1 2.32 77.1 9164 5 15 80 −3 79 46 2.2 11.4 5.2 1.92 76.9 93 64 5 25 70 −3 81 47 2.311.7 5.2 1.75 76.9 95 65 5 35 60 −3 84 47 2.3 11.9 5.2 1.65 76.9 98 65 545 50 −3 86 47 2.3 12.0 5.2 1.55 77.0 100 65 5 55 40 −4 89 47 2.4 12.25.2 1.43 77.0 102 66 5 65 30 −4 91 47 2.4 12.3 5.2 1.29 77.0 103 66 5 7520 −4 93 47 2.4 12.3 5.2 1.14 76.9 104 66 5 85 10 −4 95 47 2.4 12.3 5.20.97 76.8 104 66 15 5 80 1 80 42 2.9 13.1 4.5 5.61 79.4 120 66 15 15 700 83 43 2.9 13.2 4.6 4.89 79.1 119 66 15 25 60 0 85 43 2.9 13.3 4.7 4.5479.0 121 67 15 35 50 −1 88 43 2.9 13.5 4.7 4.28 78.9 123 67 15 45 40 −190 43 2.9 13.7 4.7 4.00 78.7 124 67 15 55 30 −1 93 43 2.9 13.7 4.8 3.7078.6 125 67 15 65 20 −2 95 44 2.9 13.8 4.8 3.37 78.4 125 67 15 75 10 −298 44 2.8 13.7 4.9 3.04 78.1 125 67

Example 6 Results for a Moderate-Temperature Cooling, Comparison withR404a and R407c

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COP/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 48R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 114 56 HFC-32 HFC-134a HFO-1234ze25 5 70 2 84 42 3.7 15.4 4.2 7.24 80.4 100 59 25 15 60 2 85 42 3.7 15.74.2 6.76 80.3 100 59 25 25 50 1 86 43 3.8 16.0 4.3 6.30 80.3 101 59 2535 40 1 87 43 3.8 16.3 4.3 5.87 80.2 101 58 25 45 30 0 88 44 3.8 16.64.3 5.43 80.0 102 58 25 55 20 0 89 44 3.9 17.0 4.4 5.01 79.9 103 58 2565 10 0 90 45 3.9 17.3 4.4 4.64 79.7 104 58 35 5 60 2 89 42 4.3 17.5 4.17.49 80.8 115 59 35 15 50 2 90 42 4.3 17.7 4.1 7.03 80.7 116 59 35 25 402 91 43 4.4 18.0 4.1 6.55 80.6 116 59 35 35 30 1 92 43 4.4 18.4 4.2 6.0580.5 116 59 35 45 20 1 93 44 4.4 18.7 4.2 5.56 80.3 117 58 35 55 10 0 9544 4.4 19.0 4.3 5.12 80.2 117 58HFO-1234yf/HFC-32/HFO-4234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COP/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 48R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 114 56 HFO-1234yf HFC-32HFO-1234ze 5 25 70 2.4 83 42 3.7 15.4 4.1 7.44 80.6 100 59 15 25 60 2.382 41 3.9 15.8 4.1 7.32 80.8 102 59 25 25 50 2.2 82 41 4.1 16.3 4.0 7.1580.9 105 58 35 25 40 1.9 81 42 4.2 16.9 4.0 6.92 80.9 108 59 45 25 301.6 81 42 4.4 17.5 4.0 6.59 80.9 111 58 55 25 20 1.2 81 42 4.5 18.1 4.06.20 80.9 113 58 65 25 10 0.8 81 43 4.6 18.7 4.0 5.83 80.9 113 57 5 3560 2.6 88 42 4.4 17.5 4.0 7.63 80.9 116 59 15 35 50 2.4 87 41 4.5 18.04.0 7.40 81.0 119 59 25 35 40 2.1 87 42 4.7 18.7 3.9 7.05 81.1 122 59 3535 30 1.6 87 42 4.9 19.4 4.0 6.58 81.0 124 58 45 35 20 1.0 87 43 5.120.3 4.0 6.01 80.9 125 57 5 50 45 1.9 97 43 5.2 20.8 4.0 6.88 80.9 13658 15 50 35 1.2 96 43 5.4 21.6 4.0 6.25 80.9 138 58 25 50 25 0.4 96 445.6 22.6 4.1 5.43 80.8 139 57HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COP/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 48R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 114 56 HFC-32 HFC-152a HFO-1234ze25 5 70 2 85 41 3.6 15.1 4.2 7.26 80.4 99 60 25 15 60 2 87 41 3.5 15.04.3 6.82 80.2 100 60 25 25 50 1 90 41 3.5 15.2 4.3 6.42 80.1 100 60 2535 40 1 92 42 3.5 15.3 4.4 5.98 79.8 101 60 25 45 30 1 95 42 3.4 15.44.5 5.54 79.6 101 60 25 55 20 0 98 42 3.4 15.4 4.5 5.15 79.4 100 60 2565 10 0 100 42 3.3 15.3 4.6 4.84 79.1 100 60 35 5 60 3 90 41 4.2 17.14.1 7.89 80.8 116 60 35 15 50 3 92 41 4.1 17.0 4.1 7.68 80.7 116 60 3525 40 2 95 41 4.1 17.1 4.2 7.18 80.4 116 60 35 35 30 2 98 42 4.0 17.34.3 6.61 80.2 115 60 35 45 20 1 101 42 3.9 17.3 4.4 6.17 79.9 115 60 3555 10 1 103 42 3.8 17.2 4.5 5.96 79.6 114 60 50 5 45 2 98 42 5.0 20.34.0 7.48 80.9 135 59 50 15 35 2 101 42 4.9 20.3 4.1 7.22 80.7 135 59 5025 25 2 105 43 4.8 20.4 4.2 6.59 80.3 133 58 50 35 15 1 108 43 4.7 20.44.4 6.20 80.0 132 58 50 45 5 1 111 43 4.6 20.2 4.4 6.34 79.8 131 58

Example 7 Results for a Moderate-Temperature Heating, Comparison withR404a and R407c

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COPc/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 58R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 107 64 HFC-32 HFC-134a HFO-1234ze35 5 60 2 89 42 4.3 17.5 4.1 7.49 80.8 104 66 35 15 50 2 90 42 4.3 17.74.1 7.03 80.7 105 66 35 25 40 2 91 43 4.4 18.0 4.1 6.55 80.6 105 66 3535 30 1 92 43 4.4 18.4 4.2 6.05 80.5 106 65 35 45 20 1 93 44 4.4 18.74.2 5.56 80.3 106 65 35 55 10 0 95 44 4.4 19.0 4.3 5.12 80.2 107 65 50 545 2 98 43 5.1 20.6 4.0 6.86 80.9 122 65 50 15 35 1 98 43 5.1 20.9 4.16.30 80.8 122 65 50 25 25 1 100 44 5.1 21.2 4.1 5.70 80.6 122 65HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp T sortie Sortie sortie cond evap P cond P Taux rendement %COP/ Composition (%) évap (° C.) comp (° C.) (° C.) (bar) (bar) (p/p)Glide comp % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 58R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 107 64 HFO-1234yf HFC-32HFO-1234ze 35 25 40 1.9 81 42 4.2 16.9 4.0 6.92 80.9 100 67 45 25 30 1.681 42 4.4 17.5 4.0 6.59 80.9 102 66 55 25 20 1.2 81 42 4.5 18.1 4.0 6.2080.9 104 66 65 25 10 0.8 81 43 4.6 18.7 4.0 5.83 80.9 105 65 5 35 60 2.688 42 4.4 17.5 4.0 7.63 80.9 105 66 15 35 50 2.4 87 41 4.5 18.0 4.0 7.4081.0 108 66 25 35 40 2.1 87 42 4.7 18.7 3.9 7.05 81.1 111 66 35 35 301.6 87 42 4.9 19.4 4.0 6.58 81.0 114 66 45 35 20 1.0 87 43 5.1 20.3 4.06.01 80.9 115 65 5 50 45 1.9 97 43 5.2 20.8 4.0 6.88 80.9 124 65 15 5035 1.2 96 43 5.4 21.6 4.0 6.25 80.9 126 65HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COP/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 58R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 107 64 HFC-32 HFC-152a HFO-1234ze35 5 60 3 90 41 4.2 17.1 4.1 7.89 80.8 104 67 35 15 50 3 92 41 4.1 17.04.1 7.68 80.7 104 67 35 25 40 2 95 41 4.1 17.1 4.2 7.18 80.4 104 67 3535 30 2 98 42 4.0 17.3 4.3 6.61 80.2 104 67 35 45 20 1 101 42 3.9 17.34.4 6.17 79.9 103 66 35 55 10 1 103 42 3.8 17.2 4.5 5.96 79.6 103 67 505 45 2 98 42 5.0 20.3 4.0 7.48 80.9 122 66 50 15 35 2 101 42 4.9 20.34.1 7.22 80.7 122 66 50 25 25 2 105 43 4.8 20.4 4.2 6.59 80.3 121 65 5035 15 1 108 43 4.7 20.4 4.4 6.20 80.0 120 65 50 45 5 1 111 43 4.6 20.24.4 6.34 79.8 119 65

Example 8 Results for a Moderate-Temperature Cooling, Comparison withR410a

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COP/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R410A −5 103 50 6.8 30.7 4.5 0.07 79.5 100 50HFC-32 HFC-134a HFO-1234ze 65 5 30 0 107 45 5.8 24.0 4.1 5.22 80.6 10057 65 15 20 0 108 45 5.8 24.3 4.2 4.52 80.4 99 57 65 25 10 −1 110 46 5.824.6 4.3 3.93 80.3 99 56 80 5 15 −2 118 47 6.3 27.5 4.3 2.83 80.0 107 5580 15 5 −3 119 48 6.3 27.6 4.4 2.33 79.9 106 55 90 5 5 −4 126 49 6.629.6 4.5 1.23 79.6 111 54HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COP/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R404A −5 77 50 5.2 23.0 4.5 0.37 79.7 100 58R407C −1 89 45 4.5 19.8 4.4 4.46 79.9 107 64 HFC-32 HFC-152a HFO-1234ze35 5 60 3 90 41 4.2 17.1 4.1 7.89 80.8 104 67 35 15 50 3 92 41 4.1 17.04.1 7.68 80.7 104 67 35 25 40 2 95 41 4.1 17.1 4.2 7.18 80.4 104 67 3535 30 2 98 42 4.0 17.3 4.3 6.61 80.2 104 67 35 45 20 1 101 42 3.9 17.34.4 6.17 79.9 103 66 35 55 10 1 103 42 3.8 17.2 4.5 5.96 79.6 103 67 505 45 2 98 42 5.0 20.3 4.0 7.48 80.9 122 66 50 15 35 2 101 42 4.9 20.34.1 7.22 80.7 122 66 50 25 25 2 105 43 4.8 20.4 4.2 6.59 80.3 121 65 5035 15 1 108 43 4.7 20.4 4.4 6.20 80.0 120 65 50 45 5 1 111 43 4.6 20.24.4 6.34 79.8 119 65HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COP/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R410A −5 103 50 6.8 30.7 4.5 0.07 79.5 100 50HFC-32 HFC-152a HFO-1234ze 65 5 30 1 108 45 5.7 23.7 4.2 5.78 80.5 10057 65 15 20 0 112 45 5.5 23.8 4.3 5.37 80.1 99 56 65 25 10 0 116 46 5.423.8 4.4 5.12 79.7 97 56 80 5 15 −2 120 47 6.2 27.3 4.4 3.27 79.9 106 5580 15 5 −2 124 48 6.0 27.2 4.5 3.36 79.5 105 54 90 5 5 −3 127 49 6.529.5 4.5 1.69 79.5 110 54

Example 9 Results for a Moderate-Temperature Heating, Comparison withR410a

HFC-32/HFC-134a/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COPc/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R410A −5 103 50 6.8 30.7 4.5 0.07 79.5 100 59HFC-32 HFC-134a HFO-1234ze 80 5 15 −2 118 47 6.3 27.5 4.3 2.83 80.0 10362 80 15 5 −3 119 48 6.3 27.6 4.4 2.33 79.9 103 63 90 5 5 −4 126 49 6.629.6 4.5 1.23 79.6 108 62HFO-1234yf/HFC-32/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COP/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R410A −5 103 50 6.8 30.7 4.5 0.07 79.5 100 59HFO-1234yf HFC-32 HFO-1234ze 5 80 15 −2 118 48 6.4 28.0 4.4 2.50 80.0104 62 15 80 5 −4 117 49 6.6 29.2 4.4 1.10 79.7 104 61 5 90 5 −4 125 496.7 30.2 4.5 0.74 79.6 108 61HFC-32/HFC-152a/HFO-1234ze mixture:

Temp Temp evap comp T cond outlet outlet outlet evap P cond P Ratio comp% COPc/ Composition (%) (° C.) (° C.) (° C.) (bar) (bar) (w/w) Glideefficiency % CAP COPLorenz R410A −5 103 50 6.8 30.7 4.5 0.07 79.5 100 59HFC-32 HFC-152a HFO-1234ze 80 5 15 −2 120 47 6.2 27.3 4.4 3.27 79.9 10362 80 15 5 −2 124 48 6.0 27.2 4.5 3.36 79.5 101 62 90 5 5 −3 127 49 6.529.5 4.5 1.69 79.5 107 61

Example 10 Data Regarding the Quasi-Azeotropic Mixtures

HFC-32/HFO-1234yf/HFO-1234ze mixture:

Psat Past HFO- HFO- Temperature liquid vapor % diff in 1234yf HFC-321234ze (° C.) (bar) (bar) pressure 20 70 10 −5 6.4 5.9 9 28 70 2 −5 6.56.2 5 15 75 10 −5 6.5 6.0 8 23 75 2 −5 6.6 6.3 4 5 80 15 −5 6.5 5.9 9 1080 10 −5 6.6 6.1 7 18 80 2 −5 6.7 6.5 3 2 86 12 −5 6.6 6.2 7 5 86 9 −56.7 6.3 5 12 86 2 −5 6.7 6.6 2 2 90 8 −5 6.7 6.4 4 5 90 5 −5 6.8 6.6 3 890 2 −5 6.8 6.7 1HFC-32/HFC-134a/HFO-1234ze mixture:

Psat Past HFO- Temperature liquid vapor % diff in HFC-32 HFC-134a 1234ze(° C.) (bar) (bar) pressure 80 18 2 −5 6.4 5.8 9 86 2 12 −5 6.6 6.1 8 865 9 −5 6.6 6.1 7 86 12 2 −5 6.6 6.1 6 90 2 8 −5 6.7 6.3 5 90 5 5 −5 6.76.4 5 90 8 2 −5 6.7 6.4 5

1. A ternary composition comprising difluoromethane,1,3,3,3-tetrafluoropropene and a hydrocarbon-derived compound containingat least two fluorine atoms and having a boiling point of between −30and −20° C., which is selected from the group consisting of1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and2,3,3,3-tetrafluoropropene.
 2. The composition as claimed in claim 1,comprising from 2 to 96% of difluoromethane, from 2 to 96% of1,1-difluoroethane and from 2 to 96% of 1,3,3,3-tetrafluoropropene. 3.The composition as claimed in claim 1, comprising from 2 to 96% ofdifluoromethane, from 2 to 96% of 2,3,3,3-tetrafluoropropene and from 2to 96% of 1,3,3,3-tetrafluoropropene.
 4. The composition as claimed inclaim 1, comprising from 2 to 96% of difluoromethane, from 2 to 96% of1,1,1,2-tetra fluoroethane and from 2 to 96% of1,3,3,3-tetrafluoropropene.
 5. The composition as claimed in claim 1,comprising from 70 to 98% of difluoromethane, from 1 to 28% of2,3,3,3-tetrafluoropropene and from 1 to 15% of1,3,3,3-tetrafluoropropene.
 6. The composition as claimed in claim 1,comprising from 80 to 98% of difluoromethane, from 1 to 18% of1,1,1,2-tetrafluoroethane and from 1 to 12% of1,3,3,3-tetrafluoropropene.
 7. A vapor compression circuit comprisingthe composition as claimed in claim
 1. 8. The vapor compression circuitas claimed in claim 7, comprising a countercurrent heat exchanger.
 9. Aheat-transfer composition comprising the composition as claimed in claim1 further comprising one or more additives selected from the groupconsisting of lubricants, stabilizers, surfactants, tracers, fluorescentagents, odorous agents, solubilizing agents and mixtures thereof. 10.Heat-transfer equipment comprising a vapor compression circuitcontaining a composition as claimed in claim
 1. 11. The heat-transferequipment as claimed in claim 10, wherein said vapor compression circuitcomprises a countercurrent heat exchanger
 12. (canceled)
 13. A processfor heating or cooling a fluid or a body by means of a vapor compressioncircuit containing a heat-transfer fluid, said process successivelycomprising the evaporation of the heat-transfer fluid, the compressionof the heat-transfer fluid, the condensation of the heat fluid and theexpansion of the heat-transfer fluid, in which the heat-transfer fluidis a composition as claimed in claim
 1. 14. The process as claimed inclaim 13, in which the temperature of the fluid or the body cooled isfrom −40° C. to −10° C. and in which the heat-transfer fluid comprises acombination selected from the group consisting of: from 25 to 50% ofdifluoromethane, from 2 to 35% of 1,1-difluoroethane and from 15 to 73%of 1,3,3,3-tetrafluoropropene; from 5 to 70% of2,3,3,3-tetrafluoropropene, from 20 to 60% of difluoromethane and from 5to 75% of 1,3,3,3-tetrafluoropropene; from 20 to 60% of difluoromethane,from 2 to 60% of 1,1,1,2-tetrafluoroethane and from 5 to 78% of1,3,3,3-tetrafluoropropene; from 65 to 96% of difluoromethane, from 2 to20% of 1,1-difluoroethane and from 2 to 25% of1,3,3,3-tetrafluoropropene; from 2 to 50% of 2,3,3,3-tetrafluoropropene,from 50 to 96% of difluoromethane and from 2 to 40% of1,3,3,3-tetrafluoropropene; and from 50 to 93% of difluoromethane, from2 to 45% of 1,1,1,2-tetrafluoroethane and from 5 to 48% of1,3,3,3-tetrafluoropropene-.
 15. The process as claimed in claim 13, inwhich the temperature of the fluid or of the body cooled is from −15° C.to 15° C. and in which the heat-transfer fluid comprises a combinationselected from the group consisting of: from 2 to 20% of difluoromethane,from 2 to 85% of 1,1-difluoroethane and from 10 to 96% of1,3,3,3-tetrafluoropropene; from 5 to 75% of 2,3,3,3-tetrafluoropropene,from 2 to 20% of difluoromethane and from 10 to 83% of1,3,3,3-tetrafluoropropene; from 2 to 25% of difluoromethane, from 5 to88% of 1,1,1,2-tetrafluoroethane and from 10 to 93% of1,3,3,3-tetrafluoropropene; from 2.0 to 50% of difluoromethane, from 2to 65% of 1,1-difluoroethane and from 5 to 78% of1,3,3,3-tetrafluoropropene; from 5 to 75% of 2,3,3,3-tetrafluoropropene,from 15 to 70% of difluoromethane and from 5 to 80% of1,3,3,3-tetrafluoropropene; from 15 to 50% of difluoromethane, from 5 to65% of 1,1,1,2-tetrafluoroethane and from 10 to 80% of1,3,3,3-tetrafluoropropene; from 65 to 93% of difluoromethane, from 2 to30% of 1,1-difluoroethane and from 5 to 33% of1,3,3,3-tetrafluoropropene; from 5 to 45% of 2,3,3,3-tetrafluoropropene,from 50 to 90% of difluoromethane and from 5 to 45% of1,3,3,3-tetrafluoropropene; and from 50 to 93% of difluoromethane, from2 to 45% of 1,1,1,2-tetrafluoroethane and from 5 to 48% of1,3,3,3-tetrafluoropropene.
 16. The process as claimed in claim 13, inwhich the temperature of the fluid or of the body heated is from 30° C.to 80° C., and in which the heat-transfer fluid comprises a combinationselected from the group consisting of: from 2 to 20% of difluoromethane,from 2 to 85% of 1,1-difluoroethane and from 10 to 96% of1,3,3,3-tetrafluoropropene; from 5 to 75% of 2,3,3,3-tetrafluoropropene,from 2 to 20% of difluoromethane and from 10 to 83% of1,3,3,3-tetrafluoropropene; from 2 to 25% of difluoromethane, from 5 to88% of 1,1,1,2-tetrafluoroethane and from 10 to 93% of1,3,3,3-tetrafluoropropene; from 20 to 50% of difluoromethane, from 2 to65% of 1,1-difluoroethane and from 5 to 78% of1,3,3,3-tetrafluoropropene; from 5 to 75% of 2,3,3,3-tetrafluoropropene,from 15 to 70% of difluoromethane and from 5 to 80% of1,3,3,3-tetrafluoropropene; from 15 to 50% of difluoromethane, from 5 to65% of 1,1,1,2-tetrafluoroethane and from 10 to 80% of1,3,3,3-tetrafluoropropene; from 65 to 93% of difluoromethane, from 2 to30% of 1,1-difluoroethane and from 5 to 33% of1,3,3,3-tetrafluoropropene; from 5 to 45% of 2,3,3,3-tetrafluoropropene,from 50 to 90% of difluoromethane and from 5 to 45% of1,3,3,3-tetrafluoropropene; and from 50 to 93% of difluoromethane, from2 to 45% of 1,1,1,2-tetrafluoroethane and from 5 to 48% of1,3,3,3-tetrafluoropropene.
 17. A process for reducing the environmentalimpact of a heat-transfer equipment comprising a vapor compressioncircuit containing an initial heat-transfer fluid, said processcomprising a step of replacing the initial heat-transfer fluid in thevapor compression circuit with a final transfer fluid, the finaltransfer fluid having a GWP lower than the initial heat-transfer fluid,in which the final heat-transfer fluid is a composition as claimed inclaim
 1. 18. The process as claimed in claim 17, in which the initialheat-transfer fluid is a ternary mixture of 52% of1,1,1-trifluoroethane, 44% of pentafluoroethane and 4% of1,1,1,2-tetrafluoroethane or a ternary mixture of 52% of1,1,1,2-tetrafluoroethane, 25% of pentafluoroethane and 23% ofdifluoromethane, and in which the final heat-transfer fluid comprises acombination selected from the group consisting of: from 25 to 50% ofdifluoromethane, from 2 to 35% of 1,1-difluoroethane and from 15 to 73%of 1,3,3,3-tetrafluoropropene; from 5 to 70% of2,3,3,3-tetrafluoropropene, from 20 to 60% of difluoromethane and from 5to 75% of 1,3,3,3-tetrafluoropropene; from 20 to 60% of difluoromethane,from 2 to 60% of 1,1,1,2-tetrafluoroethane and from 5 to 78% of1,3,3,3-tetrafluoropropene; from 20 to 50% of difluoromethane, from 2 to65% of 1,1-difluoroethane and from 5 to 78% of1,3,3,3-tetrafluoropropene; from 5 to 75% of 2,3,3,3-tetrafluoropropene,from 15 to 70% of difluoromethane and from 5 to 80% of1,3,3,3-tetrafluoropropene; and from 15 to 50% of difluoromethane, from5 to 65% of 1,1,1,2-tetrafluoroethane and from 10 to 80% of1,3,3,3-tetrafluoropropene.
 19. The process as claimed in claim 17, inwhich the initial heat transfer fluid is a binary mixture of 50% ofdifluoromethane and 50% of pentafluoroethane, and in which the finalheat-transfer fluid comprises a combination selected from the groupconsisting of: from 65 to 96% of difluoromethane, from 2 to 20% of1,1-difluoroethane and from 2 to 25% of 1,3,3,3-tetrafluoropropene; from2 to 50% of 2,3,3,3-tetrafluoropropene, from 50 to 96% ofdifluoromethane and from 2 to 40% of 1,3,3,3-tetrafluoropropene; from 50to 93% of difluoromethane, from 2 to 45% of 1,1,1,2-tetrafluoroethaneand from 5 to 48% of 1,3,3,3-tetrafluoropropene; from 65 to 93% ofdifluoromethane, from 2 to 30% of 1,1-difluoroethane and from 5 to 33%of 1,3,3,3-tetrafluoropropene; from 5 to 45% of2,3,3,3-tetrafluoropropene, from 50 to 90% of difluoromethane and from 5to 45% of 1,3,3,3-tetrafluoropropene; and from 50 to 93% ofdifluoromethane, from 2 to 45% of 1,1,1,2-tetrafluoroethane and from 5to 48% of 1,3,3,3-tetrafluoropropene.
 20. The process as claimed inclaim 17, in which the initial heat-transfer fluid is1,1,1,2-tetrafluoroethane, and in which the final heat-transfer fluidcomprises a combination selected from the group consisting of: from 2 to20% of difluoromethane, from 2 to 85% of 1,1-difluoroethane and from 10to 96% of 1,3,3,3-tetrafluoropropene; from 5 to 75% of2,3,3,3-tetrafluoropropene, from 2 to 20% of difluoromethane and from 10to 83% of 1,3,3,3-tetrafluoropropene; and from 2 to 25% ofdifluoromethane, from 5 to 88% of 1,1,1,2-tetrafluoroethane and from 10to 93% of 1,3,3,3-tetrafluoropropene.